Study On Activated Carbon Prepared By Excess Sludge And Its Adsorption Property Of Hydrogen Sulfide

With the increasing global emphasis on water environment protection,a lot of sewage treatment plants were built up.These plants produced a large number of excess sludge which seriously harms to human health and ecological environment.Seeking the disposal way of residual sludge is particularly important.In this paper,with the surplus sludge of sewage treatment plant as a raw material,through orthogonal test,a series of sludge activated carbon were prepared by the pyrolysis carbonization based on the raw material of excess sludge,with ZnC12,KOH and H3PO4 respectively being used as different activator.By using H2S penetration time as the evaluation index,optimum process conditions of the preparation process was researched.Some characterization methods such as SEM,FI-IR,specific surface area and pore structure analysis were employed in order to analyze the structure of sludge activated carbon.The results showed that the adsorption performance of the sludge activated carbon prepared by ZnCl2 or KOH as activator was better than that prepared by H3PO4 as activator.Especially under the condition of the ZnCl2 concentration was 60%,activation temperature was 600?,activation time was 2h,and the mass ratio of sludge and activatorwas 1:2,the penetration time of adsorbing H2S could reach to 443 minutes,iodine number and methylene blue value respectively were 379.74 mg/g and 27.76 mg/g,however the H2S penetration time of sludge activated carbon prepared by H3PO4 as activator was only 6 minutes.It almost has no ability of adsorption.Structure analysis show that the surface of sludge activated carbon prepared by H3PO4 as activator was rough and visible hole was rare.The surface of sludge activated carbon with ZnCl2 or KOH as activator distributes a lot of pore,and they are mainly mesoporous.The porous structrure is not only benefit to adsorbing H2S,but also benefit to carrying micro mass.In order to further improve the adsorption performance of H2S,CuO was loaded on the surface of sludge activated carbon using liquid direct precipitation meanwhile,its structure and cure/regeneration properties were analyzed.The results showed that the CuO loaded on the sludge activated carbon was nano materials.The particle was stick,with its size around 20 nm.The adsorption H2S penetration time increased nearly 31.42%than the unsupported sludge activated carbon.Although the adsorption performance of H2S after regeneration obviously decreased,the change scale of desulfurization activity was small when the regeneration times increased.In conclusion,the sludge activated carbon prepared by using excess sludge can adsorb stench gas-H2S.This study not only realizes the resourcization and reduction of excess sludge disposal,but also achieves the waste control by waste and the purpose of changing waste material into the valuables.